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Finding the Fourth Proportional to 747.78, 1,121.82 and 285.56

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Solution

The fourth proportional to 747.78, 1,121.82 and 285.56 is: 428.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    747.78 : 1,121.82 = 285.56 : x
  2. Step 2: Convert to fraction form
    747.78/1,121.82 = 285.56/x
  3. Step 3: Cross multiply
    747.78x = 1,121.82 × 285.56
  4. Step 4: Simplify right side
    747.78x = 320,346.92
  5. Step 5: Solve for x
    x = 320,346.92/747.78
  6. Step 6: Final answer
    x = 428.40

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.